package com.zhengbo.flink.demo.base.utils;

/**
 * gps纠偏算法，适用于google,高德体系的地图
 * <p>版权所有： 版权所有(C)2016-2099</p>
 * <p>公   司： 优行科技 </p>
 * <p>内容摘要： </p>
 * <p>其他说明： </p>
 * <p>完成日期：2017/10/30</p>
 *
 * @author 4kings
 * @version 1.0
 */
public class GpsCorrect {
	final static double pi = 3.14159265358979324;
	final static double a = 6378245.0;
	final static double ee = 0.00669342162296594323;

	public static void transform(double wgLat, double wgLon, double[] latlng) {
		if (outOfChina(wgLat, wgLon)) {
			latlng[0] = wgLat;
			latlng[1] = wgLon;
			return;
		}
		double dLat = transformLat(wgLon - 105.0, wgLat - 35.0);
		double dLon = transformLon(wgLon - 105.0, wgLat - 35.0);
		double radLat = wgLat / 180.0 * pi;
		double magic = Math.sin(radLat);
		magic = 1 - ee * magic * magic;
		double sqrtMagic = Math.sqrt(magic);
		dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);
		dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);
		latlng[0] = wgLat + dLat;
		latlng[1] = wgLon + dLon;
	}

	private static boolean outOfChina(double lat, double lon) {
		if (lon < 72.004 || lon > 137.8347)
			return true;
		if (lat < 0.8293 || lat > 55.8271)
			return true;
		return false;
	}

	private static double transformLat(double x, double y) {
		double ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x));
		ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;
		ret += (20.0 * Math.sin(y * pi) + 40.0 * Math.sin(y / 3.0 * pi)) * 2.0 / 3.0;
		ret += (160.0 * Math.sin(y / 12.0 * pi) + 320 * Math.sin(y * pi / 30.0)) * 2.0 / 3.0;
		return ret;
	}

	private static double transformLon(double x, double y) {
		double ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));
		ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;
		ret += (20.0 * Math.sin(x * pi) + 40.0 * Math.sin(x / 3.0 * pi)) * 2.0 / 3.0;
		ret += (150.0 * Math.sin(x / 12.0 * pi) + 300.0 * Math.sin(x / 30.0 * pi)) * 2.0 / 3.0;
		return ret;
	}

	/**
	 * 通过经纬度获取距离(单位：米)
	 */
	public static double getDistance(double lng1, double lat1, double lng2,
									 double lat2) {
		lng1 *= 0.01745329251994329D;
		lat1 *= 0.01745329251994329D;
		lng2 *= 0.01745329251994329D;
		lat2 *= 0.01745329251994329D;
		double var12 = Math.sin(lng1);
		double var14 = Math.sin(lat1);
		double var16 = Math.cos(lng1);
		double var18 = Math.cos(lat1);
		double var20 = Math.sin(lng2);
		double var22 = Math.sin(lat2);
		double var24 = Math.cos(lng2);
		double var26 = Math.cos(lat2);
		double[] var28 = new double[3];
		double[] var29 = new double[3];
		var28[0] = var18 * var16;
		var28[1] = var18 * var12;
		var28[2] = var14;
		var29[0] = var26 * var24;
		var29[1] = var26 * var20;
		var29[2] = var22;
		double var30 = Math.sqrt((var28[0] - var29[0]) * (var28[0] - var29[0])
				+ (var28[1] - var29[1]) * (var28[1] - var29[1])
				+ (var28[2] - var29[2]) * (var28[2] - var29[2]));
		return Math.asin(var30 / 2.0D) * 1.27420015798544E7D;
	}
}
